Electric safety switch and plug coupling



July 21, 1925.. y

A `A. W. LUNDSTROM ELEC'LRIC SAFETY SWITCH AND PLUG COUPLING Filed April- 17, 192s Inventcf .1 AX@ WLundstTQm,

...Patented July 21, 19.25..

T JNlTlazD STATES,l PAT NTtO-F 4Axnr. w. LUNnsTRoM, or New Yoax, N. Y., AssrGNon To GENERAL ELECTRIC conc- PANY, A CORPORATION or NEW Yo-Rx.

ELECTRIC SAFETY SWITCH AND PLUG COUIL1NG.

Application ined April 17, 1923. serial-No. 632,802.

Y To all/whom t concern.

Ito

- Be it known that I, AXEL YV. LUNDsTnoM, a citizen of the United States, residing at New York, county of New York, and State v (of VNew York, have invented certain new y: and useful Improvementsin Electric Safety Switches and Plug Couplings, of which the' following is a specification.

The present 'invent-ion relates to 'hand- ,operated switches for controlling electric circuits and more-especially to safety switchi esorswitches havingv the current-carryingv the" lug inserted.

. ViTg connected to the box in any'well known parts enclosed .in y protective casings with only the hand-operating lever 'exposed outside thereofso that aworkman, withoutelec- ,i trical knowledge, may operate them in entire `safety 4to his person.

.plug contacts and cutout means; Fig.- 2 is anl enlarged plan view of theplu'g fender and a cross section of the attachment' plug; F ig.1'3 is a longitudinal sectional yelevation .ofthe safety switch with the plug With-v `fdrawn, and Fig. 4 is a similar view with e enclosing protective Casin alsoof sheet metal in three'sections2, 3, and 4, the outer sections 2 and l being rigidly manner while the middle -or door section 3 -is connected by hinges 5 to the edge of section 2 whereby it 'may be opened outwardly,

A- and at its edge opposite they hinges is a lapl strip 6 adapted to-foverlie the adjacent edge of section 4 and'c'onceal the joint betwecr those sections. 1 v y Secured to the inside bottom of the box is a slab 7 ofA insulating -material, onv the left-hand end of whichl are mounted three pairs of switch-contacts 8 and 9 and a threepole switch mechanism 10 having an actu-v is-invtheI ,form of a sheet metal box 1'w1th a', front' ating-lever or 4handle 11 extending through a slot in section 2 of the front of the casing. 9 .are electrically connected to contact clips 12 for. one end of the fuses 13, while the opposite fuse clips 14 are respectively connected to contact fingers 15 secured to the right-hand end of the slab 7 about a central guide post 16. ,Between the switch mechanism and fuses is a transverse insulating'portion 17 and between the fuses and the contact lingers is a similar partition 18 dividing the casing into three compartments lwith the middle lone disposed beneath, the

door section 3, so that when the latter is 14 are exposed. y

The'doorl'3 has on its inner side a reciprocating latch` 19 normally engaging at its free end beneath the edge ofthe fixed front section 4 and actuated by a crank 20 at the open only the fuses 13 and 4their clips l2 and inner-end of the knob 21. The rear or lefthand end of the latch 19 `has a hinged connection 22with a sliding bolt y23 normally r held against retraction or movement to the left by its end imp-inging upon the edge of a segment 24 forming part ofthe switch ac- ',tuating lever 121 and concentricv with its pivot. The segment 24 is provided with a slot 2550 disposed therein that when the switch is in fullolf position the end of the bolt 23 :may-freely enter it upon being retracted by the unlocking movement of the @door latch 19, and while in engagement with 'the notch it serves to prevent movement of the switch-lever 11, all as described and claimed -inanother application,.Serial No.

283,800, filed4 by me AApril 9, .1919.

" The fixed frontfsection 4.-,is provided with a` circular aperture l26 opposite the contact lfingers 15. forthe passage therethrough of the attachmentplug^27 and over'this aperture is a spring-pressed flap 28 hinged at 29'to the front section 4. Secured to the inside of the section is a slab 30 of insulating material, such' as indurated fibre, with a polygonal aperture 31 therein to serve as a guideway for the: plug 27. One corner 32 of the slab"`30 is cut away to provide play room for a fender paw/133 mountedV on a pivot 34 on the inside of the section 4 and'biased to the dotted line osition shown in' Fig. 2 by a. spring '35. '1" e rear end 36 of.` the pa'vvl lies in the path of the arcuate locking movement of the latch 19 so as to be ln io'vevd,thereby'and held in the position inaimed in fun ams -in Fig, 2, while the latchv is in its locking position with its bolt plane of the outer'ends ofthe plates. 38

and half waj)7 between themthe plug is provided with notches 39 of a size to per-` mit thebentf` end 37 of the paw] to freely enter, as indicatedfin Fig. 2, and prevent removal of the plug until the .switch 'is locked. in open circuit position and the latch 19 moved from engagement with the pawl.

It is to be noted that all movable parts, other than those provided with a handle, are enclosed within. the casing and that these handled parts are all located in the of the casing so that a n'umberof casingsv may be assembled side by side'without lost space. L I* While I ave shown and described the 'best embodiment of the invention known to me, .I do not desire to be restricted thereto.

What I claim 'as new and desire to secure v-bv Letters Patent of the United States, is

' l. -The combination with anelectric switch and an enclosing4 protective vcasing therefor,

of attachment plug contacts located within, f ,said casing and connectible in" circuit through said swtch,"said casing having an i opening opposite said contacts for the passagev of,y thev plug. .td said contacts, fender means' mounted` within said casing for preventing attachment ordetachment of said plug,1 and hand-operated means vcoacting withsaid switch,l andsaid fender means for preventing closing of said switch while said fender meansisin retracted position 'my hand this and to. lock said fender in operative position when the switch is freed. Y

2. The combination with anelectric switch and an venclosing protective casing therefor,- o attachment plug contacts located within said casing and -connectible in circuit preventing entranceor removal of said' plug, and hand-operated means co-acting with said switch and said fender to revent closure ofthe switch while the fender is vinretractive condition and to prevent retraction of the fender while Vthe switch is in closing condition."l

3. The combination with an electric'switch through said switch, said casing-having a plug opening therein oppositesa1d contacts, v A, a fender4 mounted within'said casing for and an enclosing protective casing therefor, of attachment plug contacts mounted within said casing and connectible in eircuit through said switch, said casing having an openingoppomte said contacts for the introduction of a plug` thereto, a fender pawl pivotally mounted within said casing adjacent the said plug opening, spring means l `'tending to move said pawl into retracted -position, and independently actuated means controlled bythe position of saidswitch OnadvanCing and holding said pawlv in` operative position.

4. The combination with an electric switch vand thermall cutout, of an enclosing *protectivecasing therefor having a door opposite said cutout, attachment plug contacts' mounted in said casing and connectible in circuit. through said switch and cutout, said casin having' a assade o enin therein ,t

opposite said contacts for the plug, a plug Jfender mounted adjacentsaid passage opening, and a :handoperated latch for the said door operating to actuate and hold the Said fender in operative position.

In witness whereof, I have hereunto set 13 day o'f'April, 1923. AXEL W. LUNDSTROM. 

